In recent times all the major web browsers have made serious leaps in terms of speed thanks to improvements in HTML parsing, JavaScript engines, and the arrival of hardware accelerated rendering. As differences in performance become less apparent, it’s becoming more and more important for companies like Google and Microsoft to differentiate their browsers in other ways. Lately, they’ve taken to trumpeting advances in browser security — and with the arrival of the Chrome 17 beta, Google is expanding its browser’s malware defenses.

Chrome has always offered a decent level of protection by tapping into Google’s SafeBrowsing intelligence. In fact, a report recently suggested that Google might have been boosting Chrome’s SafeBrowsing abilities by giving it preferential access to bits that were off-limits to competing browsers like Firefox and Safari. In Chrome 17, Google is taking a page from Microsoft’s book on malware protection.

Chrome already prompts users when downloading certain file types like .EXE or .MSI, but it lacks the ability to offer any kind of insight as to whether or not downloads are actually malicious. It’s merely a warning to remind users to think carefully before saving files onto their hard drives. Chrome 17 now checks downloads against SafeBrowsing data — if a file is known to be malicious or originates from a site that has a reputation for pushing malware, Chrome will sound the alarm. The official blog post makes it clear that no mechanism like this is perfect, and it’s still a step behind the protection offered by Internet Explorer 9.

Because it’s essentially definition-based, Chrome’s new malware defense — although improved — isn’t quite as adaptable as Microsoft’s reputation-based blocking. Regardless of which system offers better protection in real world use, this is a change that will help users avoid malware infections and online booby traps pushing fake antivirus software.

The new release isn’t all about security, either. Chrome 17 also adds some new intelligence that melds its existing pre-rendering abilities with the power of the Omnibox. When you begin typing a URL that Chrome has learned you’re likely to visit, pre-rendering will kick in and fetch the page. When you finish typing and hit enter or mouse up to the suggested URL and click through, the page appears to load more rapidly — because Chrome’s been pulling down bits in the background. It won’t always make a big difference, but when Google has built a reputation for offering a blazing fast browser, fractions of a second count.

Grab the new Chrome 17 beta release from Google, or restart your browser if you’re already running that channel to update it and try out the new features.